1. Field of the Invention
The present invention relates to a vulcanizing mold setting apparatus for setting a vulcanizing mold on a vulcanizing machine and, more particularly, to a tire vulcanizing mold setting apparatus capable of automatically setting a tire vulcanizing mold on a vulcanizing machine.
2. Description of the Prior Art
A tire vulcanizing machine pertinent to the present invention will be described with reference to FIG. 11. As shown in FIG. 11, a hydraulic, vertical tire vulcanizing machine 1 has a frame comprising a base frame member 2, side frame members 3 and a top frame member 4. A heat insulating plate 5 and a lower heating plate 6, i.e., a heating platen, are mounted in that order on the base frame member 2 and fastened to the base frame member 2 with bolts or the like, and a fixed mold 7 is mounted on the lower heating plate 6. A heat insulating member 10, an upper heating plate 9 and a movable mold 8 mating with the fixed mold 7 are attached in that order to a slider 11. The slider 11 holding the heat insulating member 10, the upper heating plate 9 and the movable mold 8 is moved vertically along the side frame members 3 by a lifting cylinder actuator 12 held on the top frame member 4. A pressure rod 13 extends vertically upward from the slider 11, and a cylinder 14 is fixed to the top frame member 4. The cylinder 14 applies pressure through a split nut 15 to the pressure rod 13.
The vulcanizing mold needs to be removed from the tire vulcanizing machine 1 to mount another vulcanizing mold for vulcanizing tires of another type on the tire vulcanizing machine 1 or to repair the vulcanizing mold. A vulcanizing mold mounted on the tire vulcanizing machine 1 is replaced with the vulcanizing mold shown in FIG. 11 by three steps. In a first step, the slider 11 is raised to its uppermost position and the vulcanizing mold on the tire vulcanizing machine 1 is removed, and then the vulcanizing mold assembly, i.e., the combination of the fixed mold 7 and the movable mold 8, is mounted and set temporarily on the lower heating plate 6 by a forklift truck or a hoist. In a second step, the fixed mold 7 is positioned and fixed to the lower heating plate 6. Generally, the work in the second step is carried out manually by a skilled operator by using a forklift truck or a hoist. In a third step, the slider 11 is lowered so that the upper heating plate 9 is seated on the movable mold 8, and then the movable mold 8 is fixed to the upper heating plate 9 with bolts or the like. The second step for positioning and fixing the fixed mold 7 is the most important step among those three steps.
A mold centering and clamping apparatus intended to simplify the work in the step 2 and to ensure the accurate positioning of the fixed mold 7 relative to the lower heating plate 6 is proposed in, for example, Japanese Patent Laid-open (Kokai) No. 2-130110. This known mold centering and clamping device has three mold centering members to be positioned around the fixed mold 7 at equal angular intervals, a plurality of clamping members and a single driving mechanism for simultaneously driving the plurality of clamping members. Although this known mold centering and clamping device is capable of automatically carrying out the second and third steps, the first step must be carried out manually by means of a forklift truck or a hoist, which requires much time and work to be carried out by the operator. Recently, the tire industry is required to produce tires of a variety of types in small lots, which entails frequent change of vulcanizing molds. Accordingly, if much time is spent for changing the vulcanizing mold, the rate of operation of the tire vulcanizing machine will be reduced labor cost will increase.